During the first year of this project a computer program was developed which is capable of modeling the large displacement, nonlinear, dynamic response of the lumbar spine. This includes the capability of modeling both the static and dynamic deformation of the vertebral body along with the deformation of the soft tissues. Experimental apparati have also been developed to collect structural data on the individual soft tissue components of the inter vertebral joint. These data will be generated by imposing prescribed motions to two adjacent vertebral bodies while measuring all forces and moments. Thus individual components (or the intact joint) can be studied in a variety of deformation patterns. Fixtures to study multi-vertebrae sections have been designed and will be fabricated in the near future. Studies will then be conducted to relate multi-segment studies to component studies through application of the computer model.